1. Field Of The Invention
The invention relates to a method and apparatus for monitoring an object to determine its dimension and position in space.
2. Description Of The Prior Art
It becomes desirable in certain continuous processes when producing elongated products such as wires, cables, strips, tubes, glass or metal rods to determine the dimension of the product in the production run.
In some applications it is possible to make contact with the product but there are frequent instances where the product is inaccessible as regards physical contact, for example where the product is passing through a hostile environment.
Methods of non-contact measurement of a moving product are known, which employ optical techniques. However, these methods have proven to be inaccurate because the product is generally moving freely in space and consequently movements from a fixed line of travel will occur which will unavoidably distort the ultimate measurement since the image position, upon which the measurement depends, suffers constant change.